Many medical applications require materials that are both hydrophobic and that provide a sterile barrier. One such application involves the use of such materials for packaging medical products. However, additional examples of the diverse applications to which such materials can be put include medical gowns, drapes, face masks and the like. It is also desirable in certain instances to form an antimicrobial barrier in container filters, such as Sterion.RTM. containers available from Johnson & Johnson Medical, Inc. These container filters are devices for filtering air going into a rigid or flexible container.
Materials which are hydrophobic and that provide a sterile barrier resist penetration by water and water-based liquids, including blood and urine, thereby protecting objects within or on one side of the material from contamination. Such materials are used in drapes and gowns, and as packaging material for medical instruments and supplies, among other uses.
Materials used for these applications are either inherently resistant to contaminating liquids or are chemically treated to impart resistance to contaminating liquids. One commonly used treatment to impart resistance is to apply a fluorocarbon agent to the surface of the material. One such agent is FC-808, a fluoroaliphatic ester produced by Minnesota Mining and Manufacturing Company of St. Paul, Minn. According to the U.S. Pat. No. 2,803,615, incorporated herein by reference, the perfluoro carbon group in the 3M agent is attached to a polymer backbone by a sulfamide group and an ester linkage.
Another currently used agent is ZONYL 8070 agent, a perfluoroalkyl acrylic copolymer available from E.I. DuPont de Nemours & Company, Wilmington, Del. According to U.S. Pat. No. 3,282,905, incorporated herein by reference, the perfluoro carbon group in the DuPont agent is attached to a polymer backbone by an ester linkage.
Both FC-808 agent and ZONYL 8070 agent are used to treat breathable polyolefin-based materials, such as those used in central supply room wraps and gowns. However, when these prior art fluorocarbon agents are applied to materials in a conventional fashion, such as by continuous line application, and the fluorocarbon-treated materials exposed to an oxidizing plasma sterilization process, the treated materials can lose some or all of their liquid repellency.
Thus, there is a need for a practical treatment which will render materials resistant to liquid penetration and cause them to remain repellent after sterilization by an oxidizing plasma process. Ideally, the treatment should be simple to perform. Further, the treatment should be inexpensive enough to permit disposal of the treated material after a single use.